OBSERVATIONS ON NORMAL AND DEGENERATING HUMAN OTOCONIA
OBSERVATIONS ON NORMAL AND DEGENERATING HUMAN OTOCONIA
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DOI：
10.1177/000348947608500302
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发表时间：
1976-01-01
影响因子：
1.4
通讯作者：
ALLARD, LF
中科院分区：
文献类型：
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作者：
ROSS, MD;PEACOR, D;ALLARD, LF
从尸检材料中获得的人耳石标本，代表了从胎儿到高龄的各个阶段，通过显微解剖，扫描电子显微镜，电子探针分析和X射线粉末衍射进行了研究。典型的成年耳锥结构是一个圆柱形的，有细锯齿的身体，有尖的末端;晶体学上，它对应于方解石的单晶。其他种类较少，包括连接耳石，纯菱面体和多面，可能是不成熟的形式。许多耳石在胎儿发育期间达到成人构型。在椭圆囊内，多面耳锥最多，菱形体增殖于幼年期。在年轻的成年人中，来自两个终末器官的晶体在成分上几乎相同，但囊状耳锥较大。中、老年人耳石数量减少，以球囊处耳石减少最为明显。囊状耳石在黄斑的后前方向逐渐退化;它们呈现出特定的纤维状中空外观，这是化学蚀刻或自溶无法复制的。耳石的新生和生长似乎发生在出生后，球囊和椭圆囊具有不同的特征性生长潜力。耳石相关的囊状耳锥变性似乎涉及有机物质，其在矿物质之前或同时消失。
Specimens of human otoconia obtained from autopsy material and representing various stages from fetal to advanced old age, were studied by microdissection, scanning electron microscopy, electron microprobe analysis, and x-ray powder diffraction. The typical adult otoconial configuration is a cylindrical, finely serrated body with pointed ends; crystallographically, it corresponds to a single crystal of calcite. Other, less numerous types include joined otoconia, pure rhombohedrons and multifaceted, presumably immature forms. Many otoconia achieve the adult configuration during fetal development. The multifaceted otoconia are most numerous, and the rhombohedrons proliferate, during childhood in the utricle. Crystals from both end organs are virtually identical in composition in the young adult, but saccular otoconia are the larger. In middle and advanced age the otoconia decrease in number, especially in the saccule. Saccular otoconia degenerate progressively in a posteroanterior direction across the macula; they assume a specific, fibrous, hollowed-out appearance, which is not duplicated by either chemical etching or autolysis. Neogenesis and growth of otoconia appear to occur postnatally, with different characteristic growth potentials for those of the saccule and the utricle. Age-related saccular otoconial degeneration appears to involve the organic material, which disappears either before or simultaneously with the mineral substance.